
let symbol = Symbol();
let symbol_1 = Symbol();
let symbol_2 = Symbol('这是一个新的数据类型Symbol()');

// console.log(symbol === symbol_1);//false
// console.log(`your symbol is ${symbol_2}`);//报错
// console.log(`${symbol_2.toString()}`);
 
const model = require('./model.js');
console.log(model.foo);


